As we grow older our sleep quality improves while the amount of time we spend sleeping diminishes, according to a new study. "Older subjects complain less about sleepiness, and pathological sleepiness is significantly lower than younger subjects," write the researchers, indicating that we may require less sleep as we age.
Inspired by a gap in sleep research across age and gender, a research team from Switzerland combined questionnaires that relied on participants' self-reporting and actual observation of their sleep.
This allowed them to tackle the question as to whether or not their subjects were correctly interpreting their sleep quality.
Growing older means becoming more of a morning person over time, according to the study, which found a gradual shift towards earlier bedtimes and mornings in addition to fewer complaints about daytime sleepiness from the older set.
It takes longer for women to fall asleep at night as they age, according to the study, which found the oldest female participants tossed and turned the most.
For both men and women, older people wake up more easily than young people, despite the improved sleep quality and functioning during the day.
"One possible explanation for better rating of daytime and sleep quality is an adaptation of expectations about sleep in older populations, or an acclimatisation to sleep changes over time," says co-author Gianina Luca of the University of Lausanne.
Working with 6,733 participants from Lausanne between the ages of 35 and 75 who were thought to be free of sleep disorders, the researchers conducted polysomnography (PSG) on 2,160 of them.
PSG technology records biophysical events that occur while you sleep, such as measuring the quantity and velocity of eye movements during the deep "rapid eye movement" (REM) phase of sleep.
Of this group, only 1,147 were considered free of sleep disorders after the polysomnography tests.
The researchers passed questionnaires to 5,064 of the participants, which revealed that only 2,966 were without sleep disorders.
The study, which has implications for how rampant sleep disorders are becoming, was published in the journal Taylor & Francis.